碳碳复合材料在光伏领域的应用与研究

直拉硅单晶炉、多晶硅铸锭炉是生产硅片的主要设备,其核心部件均为高纯石墨材料,随着太阳能光伏行业的发展,传统石墨材料很难满足直拉硅单晶炉和多晶铸锭炉生产设备的大型化需要,而碳碳复合材料具有良好的热物理性能,和石墨热场材料相比,具有非常大的优势,碳碳复合材料保温件、结构件和发热体将是直拉硅单晶炉和多晶铸锭炉等光伏设备热场材料的发展方向;针对碳碳复合材料结构件和保温件在使用过程中出现的问题,提出采用SiC涂层技术,来提高碳碳复合材料的使用效果和寿命,并在实验中取得了良好的效果。     

SERIES EXPANSION OF THE SABR JOINT DENSITY

Under the SABR stochastic volatility model, pricing and hedging contracts that are sensitive to forward smile risk (e.g., forward starting options, barrier options) require the joint transition density. In this paper, we address this problem by providing closed‐form representations, asymptotically, of the joint transition density. Specifically, we construct an expansion of the joint density through a hierarchy of parabolic equations after applying total volatility‐of‐volatility scaling and a near‐Gaussian coordinate transformation. We then establish an existence result to characterize the truncation error and provide explicit joint density formulas for the first three orders. Our approach inherits the same spirit of a small total volatility‐of‐volatility assumption as in the original SABR analysis. Our results for the joint transition density serve as a basis for managing forward smile risk. Through numerical experiments, we illustrate the accuracy of our expansion in terms of joint density, marginal density, probability mass, and implied volatilities for European call options.     

某污水处理厂的设计与运行

某污水处理厂一期工程规模为4×104 m3/d，采用卡鲁塞尔氧化沟处理工艺。污水处理厂总投资为4600万元，单位处理成本为0.41元/m3，单位水量电耗为0.26 kw·h/m3。运行结果表明：污水处理厂各项出水指标均能稳定达到《城镇污水处理厂污染物排放标准》（GB18918-2002）一级B标准。     

Marketing China's milk: A case study of the sales activity of dairy farmers in greater Beijing

Small farmer participation in marketing chains in emerging commodity markets and the determinants of their marketing channel choices are the center of many recent empirical and theoretical papers in the literature. The dairy sector is emerging in China. There are many fundamental questions about how farmers make dairy marketing decisions in China at the farm gate level that are unanswered. This makes the dairy sector in China a good place to study farmers in emerging marketing chains. Based on three sets of unique data collected in the mid-2000s in Greater Beijing, the analyses show that small farmers were the major producers of milk. There is no evidence that small farmers are being excluded from emerging marketing channels. One of the differences of China's dairy sector in the mid-2000s is that its marketing chain itself had many different types of agents that procure milk — and few of them were large; most were individual entrepreneurs. The high level of the competiveness may be the reason that individual agents do not have monopoly power and why small farmers can operate in the system.     

社会生产和分配的结合与人的生存和发展

社会的构成与人的生存和发展的经济基础是相关联的,社会保障人的生存和发展以生产和分配的结合为基础,而生产和分配的结合对人的生存和发展条件的保障具有决定性作用。实践表明,社会主义初级阶段,生产不能满足全体社会成员生存和发展的需要,是其最主要的社会矛盾。因此,衡量生产和分配结合的好坏,"保障人的生存和发展"这个标准要比"生产关系与生产力相适应"更好。人的发展经济学的研究要能用作制度构建的基础,这样才能够用于指导和服务于保障人的生存和发展的实践活动。对于人的生存和发展而言,经济学应该着重研究生产的组织方式与保障人的生存和发展的关系,着重研究分配的组织方式和保障人的生存和发展的关系,特别要研究生产的组织方式和分配的组织方式的结合对保障人的生存和发展的影响。     

The profitability of momentum trading strategies: Empirical evidence from Hong Kong

This paper investigates whether momentum trading strategies are profitable in the Hong Kong stock market, and examines the sources of such profitability. Momentum portfolios are significantly profitable in the intermediate term in Hong Kong, but the profits become insignificant after risk adjustment by the Chordia and Shivakumar (2001) model. The stock-specific return strategy and factor-related return strategy are analyzed to examine which portion of the total return causes stocks to enter extreme portfolios. The Chordia and Shivakumar factor-related return strategy obtains profits with a magnitude that is close to that which is attained by the total return momentum strategy. Additional evidence further supports the view that the Chordia and Shivakumar model captures momentum profits.     

企业技术创新与网络互动:珠三角173个样本

建立企业技术创新与企业网络的互动关系模型,以我国珠三角地区纺织产业集群的173家企业为样本,通过对样本数据变量进行聚类分析和相关性分析,验证了企业网络的演化与技术创新之间存在着一种协同作用关系,有效的企业网络会推动企业技术快速成长,而企业的技术创新反过来又推动企业网络不断演化以适应企业新的需求。     

社会责任与企业可持续发展研究——基于PE支持企业的视角

随着近几年企业社会责任问题凸现以及部分私募股权投资基金支持企业上市后业绩变脸,使得人们质疑私募股权投资基金的参与是否有利于支持企业社会责任的改善.文章以92家私募股权投资基金支持企业为样本,研究了社会责任与企业可持续发展的关系,结果显示企业可持续发展与对政府的责任、供应商的责任正相关,而与债权人的责任、社会的责任负相关.     

盛世走向封闭的教训值得汲取

关于苏联是怎么垮掉的,世界上论述很多,有人是说和平演变的,有人说是因为内部体制的问题.作为一个长期观察世界变化人来看,苏联兴盛起来,是开放带来的.苏联的第一个五年遍地计充分利用了1929年到1933年西方的经济危机,斯大林讲,他2/3的工厂是从美国引进的.但是战后苏联走向了封闭.     

人力资本、国内研发、技术外溢与技术进步——基于中国省际面板数据和一阶差分广义矩方法的研究

本文研究了人力资本、国内研发和技术外溢与我国全要素生产率(TFP)之间的关系,并采用动态面板数据一阶差分广义矩估计方法对1985至2005年我国28个省(自治区、直辖市)的面板数据进行了实证检验.实证表明,进口和国内研发都显著地促进了TFP水平的提高,但我们没有发现外商直接投资对TFP有显著的促进作用,不同层次人力资本中也只有高等教育人力资本促进了TFP水平的提高;实证还表明,在吸收能力指标如人力资本、国内研发、收入水平以及综合技术水平中,只有综合技术水平促进了以进口为渠道的国际技术外溢.